Built-in instrument cluster

ABSTRACT

A built-in instrument cluster for a motor vehicle includes at least one display device, which emits image-forming light and is arranged in the direct field of view of an observer, and at least one illuminated and/or self-illuminating electromechanical indicator device, which is arranged in the observer&#39;s field of view, at an angle to the display device, and is moved into the observer&#39;s field of view together with the display device via an optical combiner, which is arranged to reflect the image-forming light of the electromechanical indicator device. In order to be able to integrate such an instrument cluster into the tight spatial conditions in the instrument panel in the steering-column region, it is provided that the electromechanical indicator device is at least partially provided by light guides and/or light projectors to save depth at abutting vehicle components.

FIELD OF THE INVENTION

The present invention relates to a built-in instrument cluster for amotor vehicle having at least one display device that emitsimage-forming light, and at least one illuminated or self-illuminatingelectro-mechanical indicator unit.

BACKGROUND INFORMATION

The multitude of information that is indicated to a vehicle driver dueto the growth in the number of comfort systems such as navigationsystems, telecommunication devices, driver-assistance systems as well aswarning messages, etc., is increasing steadily. As a result, manyvehicles are already provided with so-called multi-function operatingdevices, which are disposed in the center of the console, in particular.Given such an arrangement, in order to receive the information, thedriver is forced to take his eyes away from the traffic. For thisreason, at least a portion of the information is preferably displayed inthe instrument cluster arranged in the driver's field of view in thedriving direction. Under these circumstances the problem arises thatonly a certain display area in the instrument cluster is available,besides the analog display elements for speed, rotary speed, etc.

New arrangements for instrument clusters, which are able to display alarger variety of information without dispensing with the usual analogdisplay instruments, are therefore under development.

European Published Patent Application No. 0 482 805, for example,describes an instrument cluster in which a first and a second imagesource are provided. An image-forming illumination of the first imagesource is reflected to the observer by a planar combination device andtwo additional mirrors located in the beam path of the reflected light.

The image-forming illumination of the second image source is transmittedby the combining device, and then also reflected to the observer by thetwo mirrors. The first image source may include a group ofelectromechanical indicator devices such as for speed, oil pressure, gaslevel, and display-panel lights such as the turn signal indictor, highbeam and emergency indicators. The second image source is arranged as aliquid crystal display to provide alphanumeric information, such asmessages, maintenance instructions and settings for the environment. Inthis instrument cluster, neither of the two image sources is in thedriver's direct visual field, so that a purely virtual image is created.Furthermore, in such an instrument cluster, it is difficult to controlthe parallaxes so as to prevent image distortions, the parallaxes beingcaused by the different locations of the image sources and the multiplereflections of the image-forming light of the image sources.

Moreover, Japanese Published Patent Application No. 2002-79848 describesan instrument cluster for a motor vehicle having a conventionalelectromechanical indicator device into whose display image a virtualimage of a display device, which is not arranged within the vehicledriver's field of view, is reflected via a concave, semitransparentmirror, which is arranged to pass through the image-forming light of theelectromechanical indicator device. However, using this indicatordevice, it is not possible to overcome the problem of conventionalindicator devices, i.e., displaying a greater variety of differentinformation in a rapidly comprehensible manner for the vehicle driver,since space for the reflected image of the display device must bereserved in the electromechanical indicator device.

SUMMARY

According to an example embodiment of the present invention, a displaydevice, which may be arranged as a liquid crystal display, OLED displayor any other display of this type, is arranged in the viewer's field ofview. Another electromechanical indicator device is arranged outside ofthe vehicle driver's field of view, at an angle to the display device.An optical combiner to assemble the image-forming light of the displaydevice and the electromechanical indicator device into a shared displayimage is arranged between the display device and the electromechanicalindicator device. The combiner for the image-forming light of thedisplay device is selected to be transparent and furthermore arrangedsuch that it reflects the image-forming light of the electromechanicalindicator device. These measures allow a greater variety of informationto be displayed in an organized manner in different display modes for amotor vehicle. Since the electromechanical indicator device is arrangedbelow the viewer's field of view, this instrument cluster requiresadditional space at a location within the dashboard where so far nospace has been required for instrument clusters. There is therefore aneed to further develop the instrument cluster such that it is able tobe accommodated in the limited space of a dashboard.

Example embodiments of the present invention provide a built-ininstrument cluster that, despite the use of a display device and amechanical indicator device, is so compact that it is able to beinstalled in the limited space of a dashboard within the region of thesteering column.

Accordingly, to save depth space for the vehicle components abutting thedisplay device, the electromechanical indicator device at leastpartially includes light guides and/or light projectors. The indicatordevice may include at least one pointer instrument. Depending on theplacement of the pointer instrument within the built-in instrumentcluster, different regions of the pointer instrument may be realized bylight guides.

The indicator elements of the pointer instrument, i.e., its pointer anddisplay markings, may include light guides. The ring edge of the pointerinstrument may include light guides as well. In order to reduce thedepth, the light source for feeding light into the light guides mayinclude LEDs.

The indicator elements of the pointer instrument may be at leastpartially realized by light projectors. For example, the graphic symbolsof a cover disk of the pointer instrument, i.e., the dial plate, may beproduced using light projectors. A light projector may include an LEDand a reflecting element, the reflecting element including, e.g., tworeflectors. For example, the reflectors may have optical image-formingcharacteristics and be arranged as concave mirrors, for example, inorder to achieve optical imaging.

The LEDs for feeding light into the light guides or for operating thelight projector may be arranged on a mounting board underneath the dialplate of the pointer instrument. Overall, such a combination of LEDs andmounting board may require less depth space than conventional lightsources.

The installation of the cluster instrument in the dashboard of a motorvehicle is problematic due to the control panel cross member abutting onthe rear side of the instrument cluster, the steering column connectionin the region of the front edge of this member, and the steering columnitself. A special problem in this context is not the display device,which may be positioned directly adjacent to the control panel crossmember, but the horizontally positioned electromechanical indicatordevice, which may have a substantially conventional design. Especiallyproblematic in this context is that the clearance between the built-ininstrument cluster and the steering-column connection and the actualsteering wheel should be as short as possible in order to avoid resonantfrequencies. This is in conflict with the additional requirement thatthe instrument cluster should have a specific depth in order to be ableto provide the pointer instrument of the electromechanical indicatordevice and to provide a reflected image that is satisfactory from thestandpoint of design and ergonomics. The reflected pointer instrumentshould optically float in front of the display device, so to speak,i.e., it should have a specific clearance with respect to this displaydevice. This clearance implies a reduced depth of the electromechanicalindicator device, in addition to the reduced installation space due tothe steering-column connection.

For this reason, the part of the pointer instrument provided by lightguides comes to lie in a circumferential edge region of the pointerinstrument pointing to the display device in order to save depth therefor the steering-column connection, and to provide the requiredclearance with respect to the display device. This measure allows thebuilt-in instrument cluster to nestle against the steering-columnconnection, so to speak.

Both with a view to information variety as well as design-relatedrequirements, the electromechanical indicator device may include twopointer instruments positioned on both sides of a steering column.Because of this instrument placement, which may be advantageous from thestandpoint of ergonomics, and because of the limited availableinstallation width, it is not fully possible to arrange the twoinstruments with sufficient lateral clearance so that they do notinterfere with the steering column. The pointer instruments may beshifted closer to the steering column, such that the two pointerinstruments at least partially overlap the steering column in thecircumferential edge region. In the area of these circumferential edgeregions, the pointer instruments are provided by light guides in orderto save depth there for the steering column.

Due to the reflecting by the electromechanical indicator device, whichis arranged outside the observer's field of view, with the aid of thecombiner, and the representation of the display device via the combiner,the angle between the combiner and the display device as well as thecombiner and the electromechanical indicator device should haveapproximately the same size. These angles may amount to 40° each, i.e.,80° altogether. In view of this, and since a steering-column gradient ofat least 20°, e.g., 21 to 25°, and, e.g., 23.5°, should be provided, thedisplay device and the electromechanical indicator device may be broughtinto the desired orientation with the aid of a rotary and/or tiltingadjuster device.

In the following text, example embodiments of the present invention aredescribed in greater detail with reference to the appended Figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view illustrating theconfiguration of the built-in instrument cluster according to an exampleembodiment of the present invention.

FIG. 2 is a cross-sectional view of the combination display deviceillustrated in FIG. 1 installed in a dashboard in the region of thesteering column.

FIG. 3 is a schematic view of the placement of the electromechanicalindicator device, including two pointer instruments, of the instrumentcluster with respect to the steering column of a motor vehicle.

FIG. 4 is a schematic view of another possibility of illuminating thescales or dial plates with the aid of light projectors.

DETAILED DESCRIPTION

Instrument cluster 1 for a motor vehicle shown in FIG. 1 includes adisplay device 2, which is arranged in the region of a steering wheel inthe direct field of view 3 of a vehicle driver when driving the vehicle,and an electromechanical indicator device 4, which is arranged below thedriver's field of view 3. Electromechanical indicator device 4 may be apointer instrument or a plurality of pointer instruments, e.g., in theform of dial-type gauges whose scales or dial plates are arranged to beself-illuminating or illuminated and which may have an illuminated orself-illuminating pointer to indicate the actual value. Furthermore,electromechanical indicator device 4 may include one or a plurality ofluminous area displays for warning messages, warning lights, etc.

Center axes 2 a and 4 a of display device 2 and electromechanicalindicator device 4 may be arranged at an angle a of, e.g., 80° to eachother. Disposed at an angle of 45° to the indicator device is a combiner5. This may be a planar, semitransparent mirror which lets theimage-forming light of display device 2 pass through, so that anobserver is able to perceive the display light of display device 2directly. The image-forming light of electromechanical indicator device4 is reflected by semitransparent mirror 5, so that, to an observer, thedisplay image of display device 2 appears as a virtual image 6superposed to the display image of display device 2. A diaphragm 7 madeof semitransparent material may be provided above electromechanicalindicator device 4, which is arranged to transmit the image-forminglight of the indicator device and which covers electromechanicalindicator device 4, as far as the observer is concerned, at least in thedeenergized state.

FIG. 2 is a cross-sectional view of the placement of the main componentsof the built-in instrument cluster illustrated in FIG. 1 relative tocomponents of the motor vehicle in the region of the installationlocation above steering column 10.

As illustrated in FIG. 2, the installation space for instrument cluster1 is very tight in this location behind the dashboard. Arranged behindthe installation location of display device 2 of instrument cluster 1 isa control panel crossmember 11 having a member profile element 11 a thatprojects towards display device 2. Since the conventional instrumentcluster usually comes to be arranged at the location of display device 2as well, the required space for display device 2 is indeed problematicwith respect to control panel crossmember 11, but not as critical as theposition of mechanical indicator device 4 with respect to steeringcolumn 10 and the components cooperating with steering column 10. Thisapplies, e.g., to steering-column connection 12, which extends from therear side of display device 2, approximately next to member profileelement 11 a, in a downward direction and, above all, toward the frontwith respect to steering column 10. Due to the geometry or positioningof display device 2, indicator device 4 and combiner 5 relative to eachother, as discussed earlier in connection with FIG. 1, indictor device4, by necessity, comes to lie underneath display device 2 such that,given the front end of steering-column connection 12, there isinsufficient space at least for an edge region 13 of indicator device 4pointing toward display device 2. Indicator device 4, which includes adial-type gauge or a pointer instrument, for example, in this region, isthus unable to be provided with the required depth in the conventionalmanner since there is no room for it in this region 13. As a result, tosave depth for steering-column connection 12 in the circumferential edgeregion 13, the pointer instrument arranged there at least partiallyprovided in the form of light guides or light projectors, which have lowdepth and thus make it possible to arrange indicator device 4 with lessdepth in circumferential edge region 13 compared to the remainingregion.

Also, given the limited accommodation space for instrument cluster 1,the following is pointed out with reference to FIG. 2. The clearance ofinstrument cluster 1 with respect to steering-column connection 12 andthe actual steering wheel should be as short as possible to avoidresonant frequencies. On the other hand, a certain depth is required tobe able to provide the pointer instruments of electromechanicalindicator device 4 so that a satisfactory reflected imaging of theseinstruments is achievable. The reflected pointer instruments shouldoptically float in front of the display device so to speak, which is whya corresponding clearance A between the front side of display device 2and the edge of circumferential edge region 13 of indicator device 4should be observed. The afore-mentioned tight spot betweensteering-column connection 12 and indicator device 4 is at thislocation, which is why the latter has a more shallow arrangement incircumferential edge region 13, which is able to be provided with theaid of light guides or light projectors that form a portion of theelements of indicator device 4.

Furthermore, instrument cluster 1 should be positioned such that asteering-column gradient of, e.g., at least 20°, e.g., 21° to 25°, e.g.,23.5°, is able to be provided. In addition, the angle between thesemitransparent mirror, i.e., combiner 5, and display device 2, andcombiner 5 and indicator device 4, should be identical. With an angle of40° in each case, this results in an overall angle of 80°. In order tobe able to install instrument cluster 1 in the dashboard in acorrespondingly precise and uncomplicated manner, a shared heightadjuster or rotary adjuster of display device 2 and indicator device 4may be provided together with combiner 5.

FIG. 3 illustrates the fitting of electromechanical indicator device 4with two dial-type instruments or pointer instruments 14 and 15, whichassume the position illustrated in FIG. 2 relative to steering column10. Since both pointer instruments 14 and 15 come to lie in instrumentcluster 1 at a mutual lateral offset, and since instrument cluster 1 mayhave only a specific width whereas pointer instruments 14 and 15 have arelatively large diameter for good readability, pointer instruments 14,15 come to lie such that they overlap steering column 10 at least byedge regions 16 and 17 facing each other. The available space in thislocation is as limited as in the case of circumferential edge region 13,so that pointer instruments 14, 15 are provided by light guides or lightprojectors in regions 16 and 17 in order to leave more room for steeringcolumn 10.

FIG. 4 is a schematic representation of the use of light projectors toreduce the depth of the electromechanical indicator device. A lightprojector 20 for saving depth space includes a light source 21, e.g., anLED, and a reflecting element made up of two oppositely positionedreflectors 22 and 23, which are arranged as concave mirrors, forexample, to achieve corresponding optical imaging. The reflectingelement images light 26 emitted by LED 21 onto a cover plate 24 providedwith graphic symbols 25, e.g., a dial plate, so that symbol 25 isluminous and emits light 27 to the observer. Dial plate 24 may bearranged in a conventional manner underneath the pointer of theindicator device, i.e., the dial-type gauge.

LIST OF REFERENCE CHARACTERS

-   1 instrument cluster-   2 display device-   2 a center axis-   3 field of view-   4 indicator device-   4 a center axis-   5 combiner-   6 virtual image-   7 diaphragm-   10 steering column-   11 control panel crossmember-   11 a member profile element-   12 steering-column connection-   13 circumferential edge region-   14 pointer instrument-   15 pointer instrument-   16 circumferential edge region-   17 circumferential edge region-   20 light projector-   21 LED-   22 reflector-   23 reflector-   24 dial plate-   25 graphic symbol-   26 emitted light of LED-   27 symbol light

1. A built-in instrument cluster for a motor vehicle, comprising: atleast one display device adapted to emit image-forming light andarranged in a direct field of view of an observer; at least oneelectromechanical indicator device that is at least one of (a)illuminated and (b) self-illuminating arranged in the observer's fieldof view, at an angle to the display device; and an optical combineradapted to move the indicator device into the observer's field of viewtogether with the display device, the optical combiner adapted toreflect the image-forming light of the electromechanical indicatordevice; wherein, to save depth space for vehicle components abutting theelectromechanical indicator device, the electromechanical indicatordevice at least partly includes at least one of (a) light guides and (b)light projectors.
 2. The instrument cluster according to claim 1,further comprising at least one pointer instrument that at leastpartially includes at least one of (a) light guides and (b) lightprojectors.
 3. The instrument cluster according to claim 2, whereindisplay elements of the pointer instrument include light guides.
 4. Theinstrument cluster according to claim 2, wherein display elements of thepointer instrument include light projectors.
 5. The instrument clusteraccording to claim 4, wherein graphic symbols of a cover plate of thepointer instrument are generated by light projectors.
 6. The instrumentcluster according to claim 2, wherein a ring edge of the pointerinstrument includes light guides.
 7. The instrument cluster according toclaim 2, wherein a part of the pointer instrument that includes lightguides is arranged in a circumferential edge region of the pointerinstrument pointing toward the display device to save depth for asteering-column connection.
 8. The instrument cluster according to claim1, wherein the light projector includes an LED and a reflecting element.9. The instrument cluster according to claim 8, wherein the reflectingelement includes two reflectors.
 10. The instrument cluster according toclaim 1, further comprising a light source adapted to feed light intothe light guides, the light source including LEDs.
 11. The instrumentcluster according to claim 10, wherein the LEDs are arranged on amounting plate of a pointer instrument.
 12. The instrument clusteraccording to claim 1, wherein the electromechanical indicator deviceincludes two pointer instruments arranged on both sides of a steeringcolumn.
 13. The instrument cluster according to claim 12, wherein thetwo pointer instruments are arranged at a clearance that substantiallycorresponds to a diameter of the steering column.
 14. The instrumentcluster according to claim 12, wherein, the steering column includes around diameter, a clearance of the pointer instruments is smaller thanthe diameter of the steering column, circumferential edge regions of thepointer instruments overlapping the steering column including at leastone of (a) light guides and (b) light projectors to save depth space forthe steering column.
 15. The instrument cluster according to claim 1,wherein the optical combiner includes a semitransparent mirror, thedisplay device being arranged behind the mirror in a viewing directionof the observer, the electromechanical indicator device arranged belowthe mirror.
 16. The instrument cluster according to claim 1, furthercomprising at least one of (a) a rotating device and (b) a tiltingadjuster device for the display device and the electromechanicalindicator device.